Cycloidal marine-propulsion system

ABSTRACT

A cycloidal marine-propulsion system is disclosed. The system comprises a blade-mounting disc and a plurality of propeller blades. Each of the plurality of propeller blades has a respective primary blade axis and is connected to the disc in a manner allowing the blade to be rotated about its primary blade axis independent of any about-axis rotation of every other one of the propeller blades. The system also includes a plurality of electric actuators, each actuator being connected to a respective one of the propeller blades. The system further includes a controller in communication with the electric actuators for controlling selectively each of the electric actuators.

TECHNICAL FIELD

The present technology relates generally to a cycloidal-marinepropulsion system. In some embodiments, the technology relates moreparticularly to a cycloidal marine-propulsion system comprising multipleelectric motors for controlling individually each of multiple respectivecycloidal blades.

BACKGROUND OF THE INVENTION

A cycloidal-drive propeller system is a specialized marine propulsionsystem allowing high maneuverability. The system allows change of vesselthrust to a direction and magnitude per command.

Cycloidal-drive propeller systems are used widely in vessels for whichstation keeping and high maneuverability at lower speeds are centralfunctions, such as tugboats, ferries, and offshore support vehicles. Aconventional type of cycloidal-drive propeller system is aVoith-Schneider propeller (VSP) system.

Conventional cycloidal propeller systems use heavy-duty drive enginessuch as a diesel motor drive. The drive provides input power and torquefor a relatively complex group of intermediary structures leading to acomplex mechanical gearbox and crosshead arrangement.

The drive engine of conventional systems is also connected to themechanical gearbox and slider arrangement by way of a series ofrelatively intermediate structures and a main, vertical, system shaft.The intermediate structures include, for instance, couplings (e.g.,displaceable coupling), intermediate drive shafts such as a Cardanshaft, and step-down gears, with or without one or more clutches.

During vessel movement, and especially high-vessel-speed operation, thevertical propeller blades of a cycloidal drive create undesirably highdrag in the water. The drag is particularly high under certainconditions, such as during continuous running of the vessel at highpower. The drag slows the vehicle, limiting speed and thus vesselefficiency. The drag also lowers fuel economy, requiring more power andso fuel to overcome the drag.

Due to the relatively complex intermediate structures, mechanicalgearbox, and crosshead arrangement described, response time between atriggering input—e.g., a signal transmitted in response to a captainpulling a lever—and the desired response is also undesirably high. Thecomplex mechanical drive is also noisy and causes unwanted vibration dueto unbalanced forces and couples.

BRIEF SUMMARY OF THE INVENTION

Given the aforementioned deficiencies, there is a need for a cycloidalmarine-propulsion system that reduces significantly drag formed atvertical propeller blades of the system during high-vessel-speedoperation.

The present technology accomplishes this and other goals in variousembodiments. In one embodiment, the system includes multiple electricdrives connected to respective cycloidal-propeller blades forcontrolling the respective blades selectively. Each electric driveallows complex and fine control of position and movement of the blade towhich it is connected.

Each blade can be moved, independent of movement of each of the otherblades, and independently of a rotational position of the vertical mainassembly. Both independences are distinctions compared to theconventional mechanical drive system.

Each blade can be moved in any of a variety of ways to reduce drag andaccomplish other desired functions such as creating, increasing, and/orre-directing thrust.

One way each blade can be repositioned or moved selectively is byrotating the blade about a primary, longitudinal (extending along aprimary length, usually generally vertical of the blade—reference axis117 in FIG. 1).

In a contemplated embodiment, each blade can also be tilted, or pitched,whereby an angle of a blade axis (e.g., axis 117) is changed. Thisembodiment is described more below.

In still another contemplate embodiment, all of the blade axis can bemoved toward or away from a main system axis (e.g., axis 107, FIG. 1).And each blade can be moved in more than one manner at a time—e.g.,tilted, while being rotated about its blade axis, and both at the sametime that the blade is being moved with the other blades about the mainsystem axis. These aspects are also described more below.

In addition to providing increased ability to reduce drag and in someinstances increase thrust, the individual blade control of the presenttechnology improves response time between desired blade action (e.g.,positioning or motion) resulting from input signals—e.g., an inputsignal from the controller or a vessel captain to increase speed and/oroperate in a low-drag, or energy-efficient, mode, and can also reducenoise (e.g., underwater, or underwater and noise passing to the air) andvibrations (e.g., underwater and into the vessel).

In some embodiments, efficiency, as well as fine control, are furtherpromoted by a direct electric drive. The electric drive is linkeddirectly to a main system axis shaft and, thereby, to a disc or plateholding the propeller blades. The direct electric drive also promotesquick response time between input and resulting propeller action.

Further features and advantages, as well as the structure and operationof various embodiments, are described in more detail below withreference to the accompanying drawings. The technology is not limited tothe specific embodiments described herein. The embodiments are presentedherein for illustrative purposes only. Additional embodiments will beapparent to persons skilled in the relevant art(s) based on theteachings contained herein.

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplary embodiments may take form in various components andarrangements of components. Exemplary embodiments are illustrated in theaccompanying drawings, throughout which like reference numerals mayindicate corresponding or similar parts in the various figures.

The drawings are only for purposes of illustrating preferred embodimentsand are not to be construed as limiting the technology. Given thefollowing enabling description of the drawings, novel aspects of thepresent technology will be evident to a person of ordinary skill in theart.

FIG. 1 is a perspective view of the cycloidal marine propulsion systempositioned in a marine vessel.

FIG. 2 is a side cut-away view of the system of FIG. 1.

FIG. 3 is a schematic diagram of a computing device for use inperforming functions of the present technology.

FIG. 4 is a flow chart showing operations of a method performed by thepresent technology.

DETAILED DESCRIPTION OF THE INVENTION

While exemplary embodiments are described herein with illustrativeembodiments for particular implementations, it should be understood thatthe technology is not limited thereto. Those skilled in the art withaccess to the teachings provided herein will recognize additionalmodifications, applications, and embodiments within the scope thereof,and additional fields in which the cycloidal marine-propulsion systemdescribed herein would be of significant utility.

FIG. 1—System Components

FIG. 1 is a perspective view of a cycloidal marine propulsion system100, positioned in a marine vessel 101, according to embodiments of thepresent technology. The system 100 includes a primary drive 102.

In one embodiment, the primary drive 102 is a fully electric drive.

The drive 102 is in one embodiment linked directly (e.g., withoutcomplex intermediary components such as clutches, step down or up gears)to a main vertical system shaft 104 of the system 100. The drive 102 isin this case referred to as a direct drive—e.g., a direct electricdrive.

The main shaft 104 is connected rigidly to a blade-mounting disc 106,and the two rotate about a main system axis 107 in operation.

The system 100 also includes at least one angle sensor (not shown indetail) positioned on or adjacent the main shaft 104.

A direct-drive arrangement promotes efficiency and fine control of thesystem 100, as losses from intermediate structure (e.g., couplings, suchas a displaceable coupling, intermediate drive shafts such as a Cardanshaft, and step-down gears, with or without one or more clutches) thatwould otherwise be present are avoided or greatly limited.

A direct drive arrangement, e.g., a direct electric drive, also allowsvery fast system response. By limiting intermediate structure betweenthe drive 102 and the propeller disc 106, time between an input signal,initiated by a system controller or vessel operator, and resultingpropeller action—e.g., rotation of propeller disc 106. A systemcontroller is described further below.

An electric motor 102 is in one embodiment a synchronous motor. Themotor 102 may be a wound-field or permanent-magnet type of motor. In oneembodiment, the motor 102 is an induction-type motor. And in another,the motor 102 is a reluctance-type motor.

In contemplated embodiments, the main drive 102 is not electric, or notentirely electric, being, e.g., a type of diesel engine or otherinternal combustion engine (e.g., Otto, petrol, gas turbine, etc.) Thedrive 102 can include hydraulic or pneumatic features, and connectdirectly or indirectly to the main shaft 104. The drive 102 is describedfurther below, including in connection with FIG. 2.

In one contemplated embodiment, the main assembly drive 102 includes oris connected to a geared system (not shown) for turning the main shaft104. The geared system can include a gear ring, located on a peripheryof the main shaft 104, connected to one or more pinion gears driven byone or more high speed motors.

The blade-mounting disc 106 can be referred to by other names, such asmain rotating assembly, or lower, inner, structure. The disc 106 rotateswith respect to a lower, outer, structure or frame described furtherbelow in connection with FIG. 2, and reference numeral 210.

The drive 102—e.g., direct drive—is in some embodiments controlled by acontroller using a control map. The map comprises at least one algorithmaccording to which the main shaft can be controlled. The map can use asinputs, to determine main shaft operation, any of a wide variety ofinput data, such as any of output from the on-blade or adjacent-bladeangle sensors, output from main assembly angle sensor(s), system powerbeing used, system power available, present vessel speed, vesselattitude (e.g., roll or pitch), vessel speed desired or requested (bycommand of a vessel operator or the controller 300 (FIG. 3), forinstance), wind speed, ambient water temperature, water depth presentheading and/or position, heading and/or position desired or requested(by, e.g., command of a vessel operator or the controller), a type orcharacteristic of the vessel 101, a propulsion layout, vessel-captaincommand, controller auto-generated command, etc.

The type of vessel will influence the method and type of control, sinceit is important for certain vessels to have accurate station-keepingcharacteristics, for example, platform supply vessels, or to have fasttransit times, but still require improved maneuverability, such as inthe case of ferry boats.

The propulsion layout, relative to the vessel center of gravity, orother vessel handling parameter, will require the control map to takeinto account those characteristics and parameters. For example, a tugcustomarily has two propulsion units at the furthest aft section of thehull, whereas a ferry could have the propulsion unit at the forward andafter parts of the ship.

The shaft 104 is controlled to accomplish desired vessel dynamics, suchas vessel speed, vessel-speed vector, vessel thrust, and vesselattitude.

The control map can also be configured to control the system 100 in amanner that lowers or minimizes drag created by one or more of theblades, thereby improving fuel efficiency. The control can also beperformed to maintain or produce more thrust, and can effected in lesstime than conventional systems, as mentioned above.

The control can include controlling movement of the main shaft 104.These control features are described further below in connection withFIGS. 3 and 4.

The system 100 further includes multiple actuators 108, such as electricmotors, mounted locally to the propeller disc 106. Each actuator 108 isconnected to respective system propeller blades 110.

Each blade 110 includes a distal end 112 that is positioned below abottom 113 of the vessel 101 and, during operation of the system 100,positioned in the water 115 in which the vessel 101 is positioned.

Each actuator 108 is controlled by control signals received from asystem controller, for instance, as described further below. Whileactuators 108 can be controlled to move their respective blades 110according to some relationships (e.g., each blade is controlled to bepositioned 20 degrees further in its rotation, about its blade axis,than a preceding adjacent blade on the disc 106), each actuator 108 iscontrolled to drive its respective blade 110 to move, or not move,independent of any motion of any of the other blades. That is, eachactuator/blade pair can be controlled to move while each otheractuator/blade is moved in any way, or kept from moving.

Thus, while one of the blades 110 can be rotated by a first angle in afirst direction (e.g., clockwise) about its longitudinal (e.g., usuallyvertical) axis, for instance, another of the blades 110 can becontrolled to move in any way, according to the control map, which cancontain one or more algorithms for these purposes, such as by rotatingin the same or an opposite direction by the same or another angle, orcontrolled to not move.

The system 100 also includes angle sensors on or adjacent each blade110. These sensors are in one embodiment a part of the actuators 108.For simplicity, the sensors considered illustrated by the components 108in the figures, though the sensors may be physically distinct fromand/or connected to the actuators 108.

In the illustrated embodiment, the system 100 includes five actuators108 (labeled respectively in the figures as 108A-E) connected to fiverespective propeller blades 110—110A-E. While five blades linked to fiveactuators are shown by way of example, it should be appreciated that thesystem 100 can include any number of actuators and respective blades.

The actuators 108 in some embodiments are controlled by, or include, orare, one or more electric motors. These electric motors are consideredshown by the same structure 108 in the figures. The actuators 108 insome embodiments include or are controlled by one or more other types ofdrives, such as pneumatic or hydraulic drives, considered shown by thesame structure 108 in the figures.

The actuators 108 in some embodiments include electric stepper motors.In one embodiment, the actuators are reluctance-type motors.Considerations in selecting or designing a motor of the actuators 108include any or all of responsiveness (e.g., response time), strength,robustness, durability, and noise reduction.

The actuators 108 can be operated to control velocity—speed anddirection of movement, angular and/or linear—of the respective blades110.

In operation, position of each blade 110 changes in a rotation phase ofthe system 100 in which the rotating disc 106 is being rotated. Theblades 110 being rotated by the disc 106 can create vectored thrust.

Disc rotation and/or individual blade rotations can be, as mentionedabove, controlled separately by a controller implementing a control map,or algorithm therein. The control map can use as inputs, to determinemain shaft operation, any of various inputs, such as any of output fromthe on-blade or adjacent-blade angle sensors, output from main assemblyangle sensor(s), system power being used, system power available,present vessel speed, vessel speed desired or requested (by, e.g.,command of a vessel operator or the controller 300 (FIG. 3)), windspeed, ambient water temperature, water depth present heading and/orposition, heading and/or position desired or requested (by, e.g.,command of a vessel operator or the controller), a type orcharacteristic of the vessel 101, a propulsion layout, vessel-captaincommand, controller auto-generated command, etc.

Angular speed of any of the blades 110, about a respective blade axis117 can be increased during the rotation phase to increase thrust.Angular speed of any blade, about its axis 117, can also be changed todecrease drag of the blade 110 in the water 115 when the vessel 101 ismoving.

The blades 110 are controlled individually to accomplish desired vesseldynamics—e.g., vessel speed vector, thrust, and attitude. The map, oralgorithm, can also be configured to control the vessel to lower orminimize drag created by one or more of the blades 110 against the water115, to improve fuel efficiency, and the like.

In a contemplated embodiment, thrust created by each blade 110, and/oran amount of drag caused by each blade 110 moving through the water 115,can also be affected by posture or position of the blade 110 withrespect to the disc 106—e.g., tilt angle of the blade axis 117. Any oneor more of the blades 110 can be moved selectively so that a lower,distal, tip 114 of the blade 110 moved radially outward, farther fromthe main system axis of rotation 107.

Each blade can be moved in more than one manner at a time, as mentioned.A blade can be tilted (i.e., changing an angle of the blade axis 117with respect to the main system axis 107), e.g., while it is beingrotated about its blade axis 117. And the blade can be tilted whilebeing rotated about its blade axis, and both at the same time that theblade is being moved with the other blades about the main system axis.The blade can also be translated, as a whole, toward or away from themain system axis 107 while the blade is being moved in another way, suchas being rotated about its axis 117 and/or by tilting—changing an angleof the blade axis 107 with respect to the system main axis 117.

In one embodiment, the system 100 or at least the vessel 101 includes athrust plate 116. The plate 116 is in the illustrated embodimentsuspended below the vessel 101 and positioned just below the tips 114 ofthe blades 110.

In a particular contemplated embodiment, posture of each blade 110 canalso be controlled by the controller, implementing the control map, oralgorithm, based on any of the controller inputs described herein. Thecontroller and control map or algorithm are described further belowregarding FIGS. 3 and 4.

The individual cycloidal-system blade control of the present technology,using an electric drive controlling each of multiple cycloidal propellerblades, e.g., allows complex and fine control of blade angles. Theblades can be controlled to accomplish benefits including desired vesseldynamics, such as mooring, translating, or linear movement—e.g.,straight forward, reverse, or sideways motion.

The blade control can, as referenced above, be performed, according tothe control map, in ways to reduce drag. Drag can be reduced, e.g., bycontrolling individual blades separately so that each blade 110 createsa limited amount of friction with the water 115 through which the blades110 are moving.

The map can be configured to cause each blade 100 to, at every instance,be positioned and/or moved to create a desired thrust while minimizingdrag created by the blade. The map can be configured to cause each blade100 to, at every instance, be positioned and/or moved to minimize dragwhile not performing a thrust-creating action at the moment.

An individual-blade-control arrangement also improves system response bylimiting intermediate structure between the drive 102 and the lower disc106, such as the complex mechanical gearing and sliders of theconventional VSP arrangements. In this way, time is limited between aninput signal, initiated by a system controller or vessel operator, andresulting blade positioning or motion.

FIG. 2—Cycloidal Propulsion System in More Detail

FIG. 2 is a cut-away of the system 100 of FIG. 1. The embodiment shownincludes upper bearings 202 and lower bearings 204.

The upper bearings 202 facilitate turning of the main shaft 104, orstructure connected rigidly to the axis 104, with respect to adjacentstatic structure. The upper bearings 202 are positioned between an upperinner edge 206 connected rigidly to the main shaft 104 and an upperouter edge 208 connected to framing of the vessel 101.

The lower bearings 204 facilitate turning of the main axis 104, ormoving structure connected rigidly to the main shaft 104, with respectto adjacent static structure. The lower bearings 204 are positionedbetween, for instance, a lower inner edge 210 connected rigidly to themain shaft 104 or disc 106, and a lower outer edge 212 connected toadjacent framing of the vessel 101.

FIG. 3—Computer System

FIG. 3 is a schematic diagram of a computing device 300 for use inperforming functions of the present technology. The device 300 isconfigured to control various functions of the system 100, and can alsobe referred to as a controller.

Although connections are not shown between all of the componentsillustrated in FIG. 3, the components can interact with each other tocarry out computer system functions.

The computer device 300 includes a memory, or computer-readable medium302, such as volatile medium, non-volatile medium, removable medium, andnon-removable medium. The term computer-readable media and variantsthereof, as used in the specification and claims, refer to tangible ornon-transitory, computer-readable storage devices.

In some embodiments, storage media includes volatile and/ornon-volatile, removable, and/or non-removable media, such as, forexample, random access memory (RAM), read-only memory (ROM),electrically erasable programmable read-only memory (EEPROM), solidstate memory or other memory technology, CD ROM, DVD, BLU-RAY, or otheroptical disk storage, magnetic tape, magnetic disk storage or othermagnetic storage devices.

The computer device 300 also includes a computer processor 304 connectedor connectable to the computer-readable medium 302 by way of acommunication link 306, such as a computer bus.

The processor could be multiple processors, which could includedistributed processors or parallel processors in a single machine ormultiple machines. The processor can be used in supporting a virtualprocessing environment. The processor could include a state machine,application specific integrated circuit (ASIC), programmable gate array(PGA) including a Field PGA, or state machine. References herein toprocessor executing code or instructions to perform operations, acts,tasks, functions, steps, or the like, could include the processorperforming the operations directly and/or facilitating, directing, orcooperating with another device or component to perform the operations.

The computer-readable medium 302 includes computer-executableinstructions, or code 308. The computer-executable instructions 308 areexecutable by the processor 304 to cause the processor, and thus thecomputer device 300, to perform any combination of the functionsdescribed in the present disclosure.

The instructions 308 include instructions or code 309 for controllingoperation of the system 100 (FIGS. 1 and 2). The code 309 routes, ormaps, various conditions, indicated by conditions of the vessel 101 tooutput commands for one or more controllable components of the system100. The code 309 may be referred to as a control map, mapping code,routing code, decision, and includes various algorithms defining anydesired relationships between conditions and respective commands.

Example input to the control map 309 includes those referenced above,such as any one or combination of: output from the on-blade oradjacent-blade angle sensors; output from main assembly angle sensor(s);system power being used; system power available; present vessel speed;vessel speed desired or requested (by, e.g., command of a vesseloperator or the controller 300); wind speed; ambient water temperature;water depth; heading or position desired or requested (by, e.g., commandof a vessel operator or the controller 300); a type or characteristic ofthe vessel 101; a propulsion layout; vessel-captain command; controllerauto-generated command, etc.

The control map 309 in one embodiment includes mapping, to one or moreappropriate outputs, any of various combinations of such inputs andindications communicated by the inputs. Example indications includewhether a device or condition is present/not present, on/off,percentages (e.g., percentage of vessel power being used or available),levels (e.g., vessel speed, water temperature), amounts (e.g., remainingbatter power), and/or other values (e.g., angular, linear, or otherposition relating to the main axis 104 or any propeller blade(s) 110).

Outputs include commands or signals instructing operation of one or morecomponents of the system 100. The controllable components can includethe main system drive 102 controlling rotation of the main axis 104. Asmentioned, the main drive 102 in one embodiment includes an electricdrive linked directly to the main axis 104. Aspects of the main axis 104controlled include primarily direction of rotation and speed ofrotation. The main axis rotation affects directly rotation of theblade-mounting disc 106, and so rotation of all of the blades 110, aboutthe main system axis 107.

The controllable components can also include each of the propellerblades 110. In these embodiments, the blades 110 are configured andconnected to the mounting structure or disc 106 to be movedindependently of any motion or non-movement of any of the other blades.For instance, the configuration and arrangement allows the controller300 to affect counter-clockwise rotation, about its axis 117, of a firstof the blades 110, at a first speed, while adjacent blades 110 are keptfrom rotating about their axes 117, rotated clockwise, or rotatedcounter-clockwise at a different speed, etc.

The blades 110 are in some embodiments also configured and connected tothe mounting structure or disc 106 to be moved independently of anymotion, non-movement, or rotational position of the vertical mainassembly

The mapping code 309 can be arranged in any manner connecting variousinputs (e.g., vessel-captain commands and water conditions) with pre-setcorresponding outputs (operational signals to system components). Themapping code 309 is in one embodiment arranged in an array format, suchas a matrix, connecting various conditions (e.g., inputs) tocorresponding outputs (e.g., component-specific control commands).

As a simple example of an output (e.g., control command) correspondingin the map 309 to a base condition (e.g., inputs), the input can includethe controller 300 or the vessel operator issuing, while the vessel isnot creating, or not to be creating, thrust (e.g., gliding to a dock), acommand requesting or relating to a desire to limit drag. The commandcan include or be related to a request for power or energy savings.Output in this example could include a command to the main drive 102 tostop (if not already stopped) and a command to one or any combinationincluding all blades 100 to align to a present or desired vesseldirection (i.e., so that main lateral portions of the blade(s) arefacing perpendicular to the present or desired direction) so that theblades create limited drag as they are moving through the water 115 withthe vessel 101. This may be an appropriate request, and resultingcommand, for situations in which a vessel (e.g., ferry) is approaching astop at a slow speed sufficient for the vessel to reach a destination(e.g., dock being approached) if drag is minimized. In this scenario,power and energy (e.g., fuel) are saved.

As another power/energy-saving example, a vessel operator, or thecontroller 300, can issue a command for power or energy saving vesselmovement. The movement can include starting vessel movement in anydesired direction—linear and/or turning. In the linear-movement example,the cycloid system 100 can be used to create linear vessel movement inany direction.

Because drag limits vessel movement, vessel speed can be maintained orreached with less thrust if drag is lowered. Thus, for energy savingmode, the vessel speed can be increased simply by reducing drag, withoutincreasing rotation speed of the main axis (and so discs 106 and blades110 in their collective rotation about the axis 107). Reducing drag canbe accomplished by controlling each blade 110, independently, to at alltimes have a position that limits drag under the circumstances, such asto limit drag while also being moved to create the existing thrustlevel.

While a control variable can include a rotational position of the blade110 about the main axis 107, the system is in some embodiments, asmentioned also configured so that each blade can be moved independentlyof any motion, non-movement, or rotational position of the vertical mainassembly.

One or more of the blades may at times be moved in the same manner, butgenerally each blade would be controlled to move and be positioneddifferently in this scenario. Such independent control is impossibleusing conventional cycloidal systems in which operation of each cycloidblade is linked to movement of the other blades by complex mechanicalgearing.

Blade adjustment can include controlling direction and rate of bladerotation about its axis 117.

Blade adjustment can instead or also include controlling a pitch or tiltof the blade 110—e.g., tilting the blade and its axis 117, such as bymoving a lower tip of the blade outward, away from the main system axis107.

Thrust created by a blade 110 can be increased by adjusting orcontrolling any one or more of blade movement or position about its axis117, its movement or position about the main axis 107, and a tilt angleof the blade (e.g., tilting the blade so a lower tip is moved away fromor toward the main system axis 107).

At the same time or separately, drag created by a blade 110, movingthrough the water 115, can be reduced by adjusting or controlling anyone or more of blade movement or position about its axis 117, itsmovement or position about the main axis 107, and a tilt angle of theblade (e.g., tilting the blade so a lower tip is moved away from ortoward the main system axis 107).

In a contemplated embodiment, system 100 is configured so that the blade110 may be moved in its entirety away from the main axis to accomplishdesired results (e.g., increasing thrust and/or reducing drag). The disc106 or structure connected thereto would in this case be arranged tothat each blade, or every blade together, can be moved away from themain axis 107. The lower tip of the blade 110 can be moved away from ortoward the main axis 107 by an equal amount that an upper tip of theblade 110 is moved away from or toward the axis 107, so that the bladeaxis 117 angle is kept constant in the motion. Or the blade axis 117 canangle can change in the motion, such as by the lower tip 114 being movedout more slowly than an upper tip of the blade 110.

Drag created by each blade 110 is reduced when, e.g., each blade 110 iscontrolled to an optimum rotational position (i.e., about its axis 107)vertical position according to an absolute rotational position of themain assembly relative to the intended thrust direction. The reductionof drag can be achieved by modifying the local blade rotational positionas the main assembly absolute position alters.

As a related energy-saving example, linear vessel speed can bemaintained while less power/energy is used. Due to the dragcharacteristics mentioned above, linear speed of the vessel 100 can bemaintained while one or more aspect of the system 100 can be slowed,e.g., rotation of the main axis 104, simply by adjusting the blades inreal time to reduce drag.

The control map is configured to optimize the drag reduction accordingto factors such as vessel direction, speed, and desired speed based oninputs such as those from ship sensors including those sensingparameters including attitude in roll, pitch, and yaw. In someimplementations, a greatest drag reduction effect is generated as partof providing, by blade control, steering and speed required. It will beappreciated that the blades providing thrust are not limited toproviding thrust and steering functions—e.g., the blades moving in aforward direction, meaning returning towards the thrust provisionposition, can be used to provide direction thrust. This division ofduties means that the blades may be more or less active during mainassembly vertical axis positional change. In some instances, such aswhen the vessel is in deep water, or at full-away, the position of thevessel will need correcting without reduction in thrust.

The term ‘full-away’ refers to conditions, when operating a ship,wherein the ship is clear of navigation obstacles, and the propulsionsystem of the ship can be operated to any desired power leveldesired—e.g., a level to match a mission profile. On ferries, full-awaycan involve the conditions allowing the ferry to operate at full power.Full-away can also refer to such operation of the ship (e.g., withoutlimits, at full power, etc.). On liners, full-away could include theliner operating according to a schedule at a power level of betweenabout 30 and about 100% of full load depending on factors such asdistance between ports, weather, and so on. Full-away can also refer tooperation of the propulsion system under conditions will not changenotably in substantive ways during the voyage (e.g., during a full-awayportion of the voyage) until nearing shore or navigation obstacles.

The computer system 300 further comprises an input/output (I/O) device310, or communication interface, such as a wireless transceiver and/or awired communication port. The processor 304, executing the instructions308, receives input from any of a wide variety of input sources 312 andprovides output to any of a wide variety of outputs 314.

Example input devices 312 include a temperature sensor (air, water,engine, motor, etc.), main-axis-shaft rotation-speed sensor,blade-position sensor, blade-rotation-speed sensor, other blade-positionor movement sensor, vessel-speed sensor, the controller itself(providing, e.g., a command or other input by the processor from oneportion of instructions (e.g., map 309 or other code 308) to another(e.g., the map 309), system power sensor or indicator, (by, e.g., acommand of a vessel operator or the controller 300 (FIG. 3)), wind-speedsensor, water-depth sensor, vessel-heading or position (e.g., GPS)sensor or indicator, data indicating a characteristic (e.g., anintrinsic feature) or type of the vessel 101, a sensor or indicatorexpressing data about vessel propulsion layout, data from avessel-captain, etc.

Communications to/from the device 310 can be in the form of signals,messages, or packetized data, for example. The device 310 can includeone or more transceivers, transmitters, and/or receivers. The device 310can include wired and/or wireless interfaces for communicating with theinput and output components 312, 314.

FIG. 4—Methods of Operation

FIG. 4 is a flow chart showing operations of a method 400 performed bythe present technology, according to an embodiment of the presentdisclosure.

Operations, or steps, of the method 400 are not necessarily presented inany particular order and that performance of some or all the steps in analternative order is possible and is contemplated. The steps have beenpresented in the demonstrated order for ease of description andillustration. Steps can be added, omitted and/or performedsimultaneously without departing from the scope of the appended claims.

The illustrated method 400 can be ended at any time. In certainembodiments, some or all steps of this process, and/or substantiallyequivalent steps are performed by execution of computer-readableinstructions, such as the instructions 308 including the control map309, stored or included on a computer readable medium, such as thememory 302 of the controller 300.

The method 400 begins 401 and flow proceeds to block 402, whereat thecontroller obtains a vessel-kinematic, or motion or movement, command.Though the command is termed a kinematic, or movement or motion,command, and while the command can include initiating a vessel motiondifferent than a current motion, the vessel-kinematic command can alsobe configured to (i) maintain an existing vessel motion, such as acurrent speed or direction, to (ii) stop the vehicle in any one or moredirections (angular or linear), or to (iii) maintain a non-motion state.

The obtaining operation can include receiving the command, being pushedto the processor 304. In one implementation, the obtaining includes theprocessor 304 retrieving the command—e.g., requesting and receiving thecommand.

The command in some cases is generated by the controller 300—i.e., bythe processor 304 executing instructions 308. The command can begenerated, e.g., in response to a determination by the controller 300that a vessel speed and/or direction change is needed, such as tomaintain a pre-set vessel course or to avoid an obstacle.

The command can also be initiated by an order of a vessel operator, suchas from a vessel captain selecting a hard or soft button indicating apower-saving or energy-saving mode, moving a soft or hard control forchanging vessel direction, and/or moving a soft or hard vessel controlfor changing vessel speed.

At step 404, the controller accesses and processes the control map 309.At step 406, the processor 304, executing the control map 309, obtains(e.g., receives or retrieves) input data to be used in processing thecontrol map 309. Some or all of the inputs may already be present beforeor when the processor 304 accesses the control map 309, and some or allof the inputs may be retrieved by the processor 304 in response todetermining the input(s) is/are needed in processing the control map.

The inputs may be received from any of a wide variety of sources withoutdeparting from the scope of the present technology. The inputs can bereceived from the processor 304 executing certain aspects of theinstructions, even of the control map 309. The inputs can be receivedfrom other electronic components of the vessel 100, such as any of thesensors described herein (vessel-speed, vessel-attitude,vessel-location, blade-rotation-speed, water-temperature, water-depth,etc.), or the like.

The processor 304, executing the control map 309, determines (e.g.,generates), based on the inputs received, one or more ways to adjust ormaintain operation of at least one vessel component. Block 408represents an example by which the processor 304, executing the map 309,determines a command for controlling (e.g., changing or maintaining) arotational velocity of the main axis 104.

Block 410 represents another example, by which the controller, executingthe map 309, determines (e.g., generates) one or more commands forcontrolling (e.g., changing or maintaining) a position and/or rotationalvelocity (about blade axis 117) of a blade 110. The step 410 is in someimplementations performed separately for each blade 110. The separateperformance can be made substantially simultaneously.

In some implementations, while each blade 110 is controlledindependently, as mentioned, the controller determines the one or morecommands for controlling position or rotational velocity of more thanone blade at generally the same time.

At block 412, the main-axis command determined (indicating, e.g., aninstruction to increase main-axis speed by 2 revs/min.) is provided tothe main-axis driver 102 for maintaining or changing a rotationalcharacteristic of the main shaft 104.

At block 414, the blade command determined (e.g., indicating aninstruction to increase blade rotation about the blade axis 117) isprovided to a blade actuator 108 (e.g., independent electric motor) formaintaining or changing a positional and/or movement characteristic(e.g., increasing blade rotation) for the blade 110.

As with previous step 410, the present operation 414 is in someimplementations performed separately for each blade 110. The separateperformance can be made substantially simultaneously. In someimplementations, while each blade 110 is controlled independently, viaits respective actuator (e.g., independent electric motor), asmentioned, the processor 304 can generate commands for controllingposition or rotational velocity of more than one blade at generally thesame time, and commands for various blades can be related. As mentioned,for instance, actuators 108 can be controlled to move their respectiveblades 110 according to some relationships—e.g., each blade iscontrolled to be positioned 20 degrees further in its rotation, aboutits blade axis 117, than a preceding adjacent blade 110 of the blades110 on the disc 106.

At operation 416, the controller determines whether a newvessel-kinematic command (VKC) is present. In some embodiments, theoperation 416 includes a passive function of receiving, or notreceiving, a new VKC. As provided, while the command (VKC) is termed akinematic, or movement or motion, command, and while the command caninclude initiating a vessel motion different than a current motion, thevessel-kinematic command can also be configured to (i) maintain anexisting vessel motion, such as a current speed or direction, to (ii)stop the vehicle in any one or more directions (angular or linear), orto (iii) maintain a non-motion state.

If there is no new VKC, flow proceeds along return route 417 to steps404 et seq., such as for any further processing and any new outputdeterminations that need to be made or provided in order to maintain,reach, or get closer to reaching a desired vessel state. Such subsequentiterations of the method 400 can include obtaining new (e.g., different)and/or updated sensor data at block 406.

In response to a new VKC, such as from the controller or vesselelectronics triggered by a vessel operator, at block 418, the new VKC isaccepted, stored in cache or other memory as a current VKC, or otherwiseprocessed by the processor 304 to give effect to the new VKC.

Following receiving the new VKC, flow proceeds along return route 419 tosteps 404 et seq., such as for any further processing and any new outputdeterminations that need to be made or provided in order to maintain,reach, or get closer to reaching a desired vessel state. As shown by thefigures, such subsequent iterations of the method 400 can includeobtaining new (e.g., different) and/or updated sensor data at block 406.

The process 400 can be repeated, such as to effect one or more VKCs overtime. The process 400 can be ended 421, such as by turning thecontroller 300 or the system 100 off, or a vessel operator selecting anoff or sleep-mode.

Benefits and Advantages

This section elaborates on benefits of the present technology describedabove. Benefits are achieved by the controls described herein. Thecontrol features include controlling any or all of individual-bladeposition, individual-blade motion, main-axis-shaft position, andmain-axis-shaft motion.

These controls can be achieved using, e.g., individually-controllableblades, electric-motor blade actuators, and a direct-drive (e.g.,electric motor) for main-shaft control.

One of the primary advantages of the present technology is an ability tolower power and energy used by a marine cycloidal-propulsion system. Asmentioned, noise (e.g., underwater noise and/or noise passed to the air)can also be reduced, as well as vibrations through the water, vessel,etc. The savings result in more-efficient fuel consumption, lowered fuelcost (capital cost of operation), lower emissions, and extended shiprange on the same amount of fuel.

Technical advantages of the present technology include an ability toachieve greater speeds, including greater speeds at an equivalent powerexpenditure, by reducing drag.

Another technical advantage includes improved vessel maneuverability.Improved vessel maneuverability is achievable by the ability to controleach blade 110 individually in real time.

Another benefit of the technology is a greater flexibility in designingvessels. The flexibility results from the greater maneuverability andspeeds achievable by vessels incorporating the present technology. As aresult, the vessel can be designed in previously unachievable wayswithout sacrificing maneuverability or speed.

The flexibility can also result from an ability to use any of a varietyof drives, such one or more diesel and/or electric motors to control themain drive shaft, and a distinct controllable electric motor for each ofthe plurality of cycloidal propeller blades.

CONCLUSION

Alternative embodiments, examples, and modifications that would still beencompassed by the technology may be made by those skilled in the art,particularly in light of the foregoing teachings. Further, it should beunderstood that the terminology used to describe the technology isintended to be in the nature of words of description rather than oflimitation.

Those skilled in the art will also appreciate that various adaptationsand modifications of the preferred and alternative embodiments describedabove can be configured without departing from the scope and spirit ofthe technology. Therefore, it is to be understood that, within the scopeof the appended claims, the technology may be practiced other than asspecifically described herein.

What is claimed is:
 1. A cycloidal marine-propulsion system, comprising:a blade-mounting disc; a plurality of propeller blades, each having arespective primary blade axis and being connected to the disc in amanner allowing the respective propeller blade to be rotated about itsprimary blade axis independent of any about-axis rotation of every otherone of the propeller blades; a plurality of electric actuators, eachelectric actuator being connected to a respective one of the propellerblades; and a controller in communication selectively with each of theelectric actuators for controlling each of the electric actuators. 2.The cycloidal marine-propulsion system of claim 1, wherein thecontroller is configured to control separately each of the electricactuators according to a control map.
 3. The cycloidal marine-propulsionsystem of claim 2, further comprising: a primary vertical-axis driveshaft connected to the lower disc; and a primary-axis drive connected tothe drive shaft for turning the shaft and, thereby, turning the lowerdisc, wherein the controller is further configured to control operationof the primary-axis drive according to the control map.
 4. The cycloidalmarine-propulsion system of claim 1, further comprising: a primaryvertical-axis drive shaft connected to the lower disc; and a primaryaxis drive connected to the drive shaft for turning the shaft and,thereby, the lower disc, wherein the primary-axis drive comprises anelectric motor connected directly to the primary vertical-axis driveshaft.
 5. The cycloidal marine-propulsion system of claim 1, furthercomprising: a primary vertical-axis drive shaft connected to the lowerdisc; and a primary axis drive connected to the drive shaft for turningthe shaft and, thereby, the lower disc, wherein the controller is incommunication with the primary-axis drive for controlling the driveaccording to a control map.
 6. The cycloidal marine-propulsion system ofclaim 1, wherein each of the plurality of propeller blades is connectedto the blade-mounting disc in a manner allowing each of the propellerblades to tilt independent of any tilting of every other one of thepropeller blades.
 7. The cycloidal marine-propulsion system of claim 6,wherein the controller is configured to control separately each of theelectric actuators, to control blade tilt independently, according to acontrol map.
 8. The cycloidal marine-propulsion system of claim 2,wherein the control map produces output, used in controlling separatelyeach of the electric actuators, based on at least one data inputselected from a group consisting of: on-blade sensor data;adjacent-blade-angle-sensor data; main-assembly-angle-sensor data;present system-power data; available-system-power data; presentvessel-speed data; requested-vessel-speed data; wind-speed data;ambient-water-temperature data; present-vessel-heading data;requested-vessel-heading data; present-vessel position data;requested-vessel-position data; water-depth data; water-current data;vessel-type data; propulsion-layout data; vessel-captain command; andcontroller auto-generated command.
 9. The cycloidal marine-propulsionsystem of claim 1, further comprising: a primary vertical-axis driveshaft connected to the lower disc; wherein each of the plurality ofpropeller blades is connected to the disc in a manner allowing each ofthe propeller blades to be rotated about its primary blade axisindependent of any about-axis rotation, non-rotation, and position ofthe primary vertical-axis drive shaft.
 10. A method, for controlling acycloidal-machine-propulsion system being used in a marine vessel, themethod comprising: obtaining, by a processor of a controller, avessel-kinematic command; accessing, by the processor, a control map;obtaining, by the processor, input data indicative of at least onepresent condition associated with the marine vessel; determining, usingthe vessel-kinematic command, the control map, and the input data,distinct blade-control commands for controlling independently each of aplurality of cycloidal propeller blades; and transmitting theblade-control commands to a plurality of actuators connected torespective ones of the cycloidal propeller blades.
 11. The method ofclaim 10, wherein each of the actuators comprises an electric motor. 12.The method of claim 10, wherein the vessel-kinematic command indicates arequest to stop the vessel, maintain a present motion characteristic ofthe vessel, or to maintain a present non-motion characteristic of thevessel.
 13. The method of claim 10, wherein the vessel-kinematic commandis a previous vessel-kinematic command, the method further comprising:determining whether a new vessel-kinematic command is present, andacting on the new vessel-kinematic command if present.
 14. The method ofclaim 10, further comprising: determining, using the vessel-kinematiccommand, the control map, and input data, a main-axis-drive-controlcommand for controlling a main-axis drive of thecycloidal-machine-propulsion system; and transmitting themain-axis-drive-control command to the main-axis drive.
 15. The methodof claim 10, wherein the blade-control commands request at least onechange selected from a group consisting of: a change of position of therespective cycloidal propeller blade; a change to a blade rotation abouta blade-axis; and a tiling of the cycloidal propeller blade.
 16. Themethod of claim 10, wherein: the marine vessel comprises a primaryvertical-axis drive shaft, each of the plurality of cycloidal propellerblades is connected to a blade-mounting disc in a manner allowing therespective cycloidal propeller blade to be rotated about its primaryblade axis independent of any about-axis rotation, non-rotation, andposition of the primary vertical-axis drive shaft, and determining,using the vessel-kinematic command, the control map, and the input data,distinct blade-control commands for controlling independently each ofthe cycloidal propeller blades, comprising determining blade-controlcommands for controlling the cycloidal propeller blades wherein eachcycloidal propeller blade is not limited mechanically to only one bladeposition based on about-axis rotational movement, non-movement, andposition of the primary vertical-axis drive shaft.
 17. A method forcontrolling a cycloidal-machine-propulsion system being used in a marinevessel, the method comprising: accessing, by a processor, a control map;obtaining, by the processor, input data indicative of at least onepresent condition associated with the marine vessel; determining, usingthe control map and the input data, distinct blade-control commands forcontrolling independently each of a plurality of cycloidal propellerblades; and transmitting the blade-control commands to a plurality ofactuators connected to respective ones of the cycloidal propellerblades.
 18. The method of claim 17, further comprising: determining,using the control map and the input data, a main-axis-drive-controlcommand for controlling a main-axis drive of the system; andtransmitting the main-axis-drive-control command to the main-axis drive.19. The method of claim 17, wherein: the marine vessel comprises aprimary vertical-axis drive shaft, each of the plurality of cycloidalpropeller blades is connected to a blade-mounting disc in a mannerallowing the respective cycloidal propeller blade to be rotated aboutits primary blade axis independent of any about-axis rotation,non-rotation, and position of the primary vertical-axis drive shaft, anddetermining, using the vessel-kinematic command, the control map, andthe input data, distinct blade-control commands for controllingindependently each of the plurality of cycloidal propeller blades,comprising determining blade-control commands for controlling thecycloidal propeller blades wherein each cycloidal propeller blade is notlimited mechanically to only one blade position based on about-axisrotational movement, non-movement, and position of the primaryvertical-axis drive shaft.
 20. The method of claim 17, wherein theblade-control commands request at least one of a change to a bladerotation about a blade-axis and/or a tiling of the cycloidal propellerblade.